We finally got back to Tempe this past Saturday! We unloaded the equipment and went home. I’m sure everyone was ready to sleep at least 12 hours.

Agua de Hermosillo Presentation

We started week 2 with meeting professors and students from different universities of Mexico. We attended many talks with government officials from Sonora, Mexico. As you can see on the left we met with Agua de Hermosillo, which they administer the public water of Hermosillo, Sonora. We also were invited to visit the vineyard of Grupo Alta, and we learned so much about the grape agriculture. More specifically, we learned that just by looking at a leaf we can identify which nutrients the plant is needing, such as potassium, magnesium, and others. Down below you can see the group picture with the Grupo Alta workers.

Grupo Alta Vineyard

During week 2 we also visited the Independencia aqueduct reservoir, el Novillo dam, the Distrito de Riego del Valle del Yaqui, and we had several talks addresing Sonoran water issues. Something very unique we were able to do was to visit the manglar de la Huivulai via boats. You can see a group picture of everyone super happy down below.

Manglar Site

Week 3 consisted of field work in Rayon, Sonora. The 14 experiments are as follows:

Rayon tower weir construction

Topographic survey

Isotopic partitioning of evapotranspiration at an agroecosystem

Stomatal conductance of plants

Plant water potential

Daily soil moisture/ temperature sampling

Set-up mobile eddy covariance

Balloon and quadcopter imagery

Field spectrometer sampling

Sap flow measurements

Throughfall, stemflow, and interception loss in oak forest

Geophysical survey

Community water use survey at San Miguel River

Removal of hydrometereological stations in San Miguel basin

At times we ran into difficulties with equipment not properly working, but we all worked as a team and got through the day. Below you can see pictures of several members working in different experiments.

Weir construction

Resistivity machine

Mobile tower in agricultural site

As of Week 4, the ASU members are in charge of putting away all of the field equipment and putting together a presentation that will be shown to the public sometime during the week of August 25th-29th. Please feel free to come and look-out for some of the flyers we will be posting around campus!

This year was unforgettable and we learned so much about hydrology… ONE of a kind experience.

It has been a while since my last post and since Cody had mentioned my feeling ill. I had a bad day, three days into the trip, and suffered from a fever and vomiting. Fortunately, I recovered the day after and have stayed healthy throughout the trip. I’m chalking it up to some strange reaction I had to motion sickness. Since then we have had rougher days and smoother days, but I’ve been well all the same. Actually, I’ve been better than well. I mean, I’m in out in the middle of the ocean, far from land, and no matter what direction I look in, I see blue water as far as the curve of the horizon. I’m literally floating above an entire world, full of mystery and life. That in itself seems wild and amazing, but truthfully, I’m more distracted by this incredible culture that surrounds me. I’ve been plucked from a stationary existence and dropped off in a fast-paced environment where being useful goes hand in hand with being experienced. Upon my arrival, I had absolutely zero experience with nut drivers, hose clamps, electrical tape, pear rings, shackles, and bowline knots, and even less with the incredible hardware and software of the instruments I have been strapping down and sending over the side of the ship into the cold depths below. I’ve used my hands for the first time in years, to actually build and bind and collect and disassemble. In the beginning, I didn’t know the names of the tools, or how to use them, but my determination to be useful combined with the opportunity to help has taught me a great deal in the past two weeks.

Tim’s tripod and camera ready to be sent down.

The mix of sailors and scientists makes for thorough entertainment. I’m consumed in countless stories from past decades and former jobs. When I really think of what it must be like to be a deck hand, or the Chief Scientist, or an engineer for the Alvin submersible, it’s like dreaming of an exotic life that I will never have as my own. Every detail, every memory in their lives, is unique and beautiful, yet foreign to me. I envy each of these people for their experiences, but more than that, I admire them. They have so much knowledge to share and I could easily listen for a lifetime.

A few nights ago I was given an orientation and tour of the Alvin Submersible by Jefferson, an engineer, diver, and pilot in training. We walked around the exterior of the large submersible and he explained the purposes of the instrumentation and hardware. One of the most significant features of the sub is its ability to add or subtract weight so that it can become neutral in water. Large slabs of syntactic foam make up the bodice of Alvin, along with tanks that can be filled with air as needed. The syntactic foam is made of microscopic glass spheres making it positively buoyant in water. Toward the front of the sub is a basket which holds any equipment that will be used to conduct science experiments during the dive. For example, metal cylinders were used on a few of the dives to hold samples of water. On either side of the basket are Alvin’s arms. One fairly new and dexterous, with a miniature version inside for pilot control, and the other much older and better at heavy lifting. Two metal spheres are attached to the sub behind the basket. Mercury is stored in these spheres and can be pumped around the body of the submarine to adjust tilt. The mercury exists as a liquid even in the cold depths of the ocean, and since it’s very heavy, it’s an optimal substance for weight adjustments. There are a total of five portholes, three on Alvin’s face with 17” diameters and two on either side with 12” diameters. Surrounding the crown of Alvin is an array of lights and cameras. Two spherical cameras sit on either side with 360 degree views.

Recovering Alvin after a dive.

After the walk-around, it was time to go inside. We went up to the second level of the garage and walked on top of the sub to get to the hatch. We took our shoes off and climbed down a ladder into the hole. The room was small and dark, lit by dim red LEDs among numerous controls and switches on all walls of the bowl. The pilot sits on a small stool in the middle and on either side of him are slanted floor spaces for two passengers, one port and one starboard. Directly behind the pilot is a stack of oxygen tanks, three of which are responsible for filling the sub during a normal dive. The rest of the stack is there in case of emergency or delayed recovery. Carbon dioxide scrubbers are neatly tucked on either side, along with EBAs (emergency breathing apparatus), just in case. Both passengers have their own display of video feed from the external cameras on their side of the sub. Along with each display is a hand held controller that allows the passenger to switch between multiple camera views. For instance, the starboard passenger can change the direction of a specific starboard camera (say, camera #1), hit record, then switch channels to a different starboard camera (camera #2) and do the same.

Cody inside the Alvin Submersible during his orientation.

Jefferson took his time going over the specifics, things every passenger must know before they dive, in case the pilot needs assistance or suddenly becomes incapacitated. After exiting the sub and undergoing a full orientation, the potential passenger (me!) must sign a form to be eligible for a dive. If you can’t tell already, I was more than eager to sign the form, just in case there was some small sliver of a chance that I may be able to dive. I wasn’t exactly high up on the list, but I was glad to have at least gotten my name on the list! And who knows, maybe I will meet the R/V Atlantis and Alvin again, in the near future, and get a chance to travel to the seafloor. After watching Aliens of the Deep, I’m beginning to think that I could shift my career to test instrumentation in our oceans in preparation for a mission to explore Europa’s oceans. Exploring the unknown, whether on our planet or another, is such a tantalizing notion. I feel a deep desire, an intense willingness, to sink to the bottom of the ocean, my eyes open the entire time, to catch a glimpse of the alien universe that lies beneath. It’s too tempting, for goodness sake, it’s right here! Our own home; no space shuttles necessary.

This cruise will remain a precious memory to share for as long as I live. But more than that, it has changed who I am and has gifted such inspiration. I have fallen in love out here in the Pacific, above an underwater volcano, on a research vessel, hundreds of miles from land…

Several participants looking for equipment that we will be taking to Mexico!

The preparation for the LAST campaign officially started this past Monday, July 21, 2014 at 9 am, to be precise. We have been successfully preparing for our trip to Sonora, Mexico which will last for two weeks. Professor Enrique Vivoni and 12 participants (undergraduate and graduate students from different backgrounds) will be traveling to Mexico this Sunday to accomplish several goals, which include:

Deploying instrumentation

Conducting field sampling

Visiting water infrastructure projects, and

Interacting with local water managers.

I could go on and on about every little detail, but you can further read and learn about the UMB-WEST 2012 and 2013 Campaigns by clicking on this link. I want to focus more about the experiences and challenges that make the 2014 UMB-WEST Campaign unique.

Quad-copter! Takes aerial images with a high resolution.

This year we are using a Quad-copter for the first time! We plan on taking aerial pictures of the sites, and you can see an image of it on the left <——. Something very neat about the instrument is how it can be controlled with your cellphone by simply downloading a free app! All of the participants are learning how to use the equipment that will be used to perform the different experiments in Mexico. Some of the experiments that will be completed in the next two weeks entail constructing a weir, setting up a mobile tower, complete a topographic survey, recover stations that were installed in previous years, and pass out surveys to local Sonoran neighborhoods to know their opinion in regard to water issues.

Additionally, we have been learning about GIS mapping through ArcMap and the end result can be seen in our Facebook page. The HEC-HMS hydrological model was also taught to the participants by Dr. Ted Bohn, Enrique’s Post-Doc student.

I am very excited to be part of this team because everyone is very enthusiastic, positive, and prepared to solve any problem we might run into. We are working together as a team and getting things done efficiently. Week 2 will consist of mainly meeting Mexican officials who make the decisions about water issues in Sonora, so I will basically be the reporter of the week. Hopefully I have internet access to publish the “hot” topics that are brought up during the presentations, if not once we come back from Mexico I will publish it!

Original Dive Objectives:
This dive’s primary objective is to deploy the VentCam and the Diffuse Effluent Monitoring System (DEMS) camera at the phoenix vent site and to recover the device that Bill and Kang deployed on dive 4741. Secondary objectives of this dive include taking 5L of bottom water using the small Niskin system, deploying a portable dot pattern screen analog of DEMS, and recovering one coated High Temperature HOBO from the Inferno vent. Tertiary objectives of this dive are to collect rock samples.

Accomplished Objectives on this Dive:
All objectives accomplished. The VentCam was successfully deployed, targeted onto phoenix vent focused flow, and confirmed to be operational. The DEMS camera system was successfully deployed, positioned over phoenix vent diffuse flow, and confirmed to be operational. The portable dot pattern screen was deployed, imaged and recovered. 5L of bottom water were sampled with the Niskin system at various locations. The coated High-Temperature HOBO probe was recovered from inferno vent. Rock samples were collected from regions of recent (2011 eruption) flow and old lava flow.

Yesterday I thought our optical experiments were unlikely to get in the water again and I wasn’t going to be able to go down to the bottom of the ocean in the Alvin. Today, the modems are ready to go in and I’m scheduled to dive at 6am tomorrow.

In about one hour, Greg, Amanda and I will be attaching the optical network modems onto the CTD cable. Man did we ever pull that one off the tarmac! What can I say, I don’t want to jinx anything but everything is looking good. You can’t be afraid of jinxing things when you’re a scientist at sea, one because a scientist shouldn’t believe in such things, and two because there is a constant question being asked about your readiness to deploy by other scientists. So that is what this is, and I’m here to report that we are ready.

As far as the Alvin dive goes, I was fourth on the list to go for our team (there are two teams with bottom time) but with all the weather and electronics problems that made us scrap previous dives, I got bumped. Ultimately, two experienced scientists (who had both been in Alvin numerous times in their lives) gave up their seats in order to move me up the list onto tomorrow’s dive. It was a very kind gesture. This is the new Alvin, re-designed at a cost of $41 million dollars and launched for the first time this year. They may not get a chance to go again for years. The only thing that could stop the dive from happening in ten hours from now is a freak storm that appears from nowhere or more unexpected electronics problems. The chances are in my favor and no matter what happens we’re blessed to be part of this adventure.

We have much to do at the bottom which means we have to move stuff around, take sensor readings, collect samples and take video images. We get to bring one pillow case of personal items. I’ll have extra clothes, paper and pen (no electronics allowed), and pictures of my family. I will be sitting starboard side of the ball. Sort of laying on my right side in a partial fetal position with my face pressed to the polymer window most of the time. We aren’t allowed shoes and the walls of the sphere are all padded with cushy black material so it’s really quite cozy. Actually we reside in less than half the sphere because a ladder comes down the middle and behind the ladder on one side are gas bottles (enough for many days of air). On our side of the ladder are all the controls and the three passenger positions. We have five windows to look out. One for the pilot looking out in front and two more on each side for each of the scientists. One of those two are at the small of your back so you have to twist around to your other side to look through it. If I am to ever extend my legs tomorrow I will have to ask the scientist across from me to move and make accommodation.

The only tumultuous part of the journey will be launch and recovery when the Alvin might sit for a long time bobbing about in the waves. We don’t eat breakfast but we do get lunch in the ball and we are home before dinner. The lunch consists of both PB&J and cold cut sandwiches. The cold cuts are back on the menu after a brief hiatus due to policy which forced them off when a pilot got food poisoning. Can you imagine being stuck in a small sphere at the bottom of the ocean and having to do all that in a plastic bag basically sitting on two other colleagues laps? That would have been the worst place to be in the whole ocean.

I can’t possibly end this entry that way. Let me also add that I will be back tomorrow evening to tell you what happened. I’m asking Greg to post something about his experiences thus far and to report what goes on tonight with the modems on the CTD cable too. Keep your fingers crossed for uneventful modem operations and an easy Alvin launch in the morning.

Bad news, followed by good news, followed by disaster, followed by insanely good luck, followed by bad luck, followed by a fighting chance. That about sums up the past two days and brings us up to now.

Bad news first. In the week we’ve been out here, Alvin has been able to dive only twice. From a passenger standpoint the weather is beautiful. Blue skies, sunshine, t-shirt and shorts on deck. Calm seas spread out across earth’s round dais and the sky so blue and flat, the sun’s orb so perfectly hung that the whole world appears as if through a tilt-shift lens. The Thompson (our sister ship) appears in the distance, bobbing on the horizon like a Battleship game piece. Sadly, it isn’t the weather you are experiencing that counts, but the weather that you might experience from which decisions are made.

The potential loss of life with the Alvin means that the probability of weather must be considered both during launch and recovery operations. Foul weather, or more accurately the threat of foul weather has prevented Alvin from diving twice and an electronic error prevented it from diving yesterday. Most of the experiments on the cruise rely on Alvin’s manipulators to perform. And since our CTD has been down, that left Woods Hole’s Sentry and ASU’s Sensorbots as the only two exceptions on this cruise. This emphasizes the importance of our success. Unfortunately, we’ve faced considerable setbacks, starting with a microscopic soldering error deep inside one of our boards. It wasn’t repairable at sea and forced us to go to plan B early on.

Now, the good news. Realizing the soldering error we moved to our backup electronics. Our guys on the beach (meaning our lab at ASU), scrambled to finalize some computer code for the backup plan. Their hard work, combined with Greg’s final insight into the memory writing subroutines and we had it working. That much has been true since day 3.

Now the disaster. After waiting our turn for the winch, which was busy dropping cameras with acoustic release-beacons for Alvin to play with on the bottom the following day (which never ended up happening as explained above) we got on deck with our modems at 4am. The plan was to do a short 200 meter drop and back. Looking back, I should have known something was wrong because the upward facing modem blinked off a few moments earlier than it should have less than 2 meters underwater. At that point there was nothing to do but control the winch and wait for the modems to return. When they did come up, the top housing was flooded with sea water, battery acid and some sort of congealed yellow material resembling gobs of hardened chicken fat.

Understand that the housings were specifically Alvin Dive Certified with a pressure test record down to 2-kilometers depth, which was obtained on each housings at some expense. Needless to say, we were crushed and likely everything inside was too. High pressure saltwater and powered electronics don’t mix. Think dropping your $100,000 computer (you’ve got one of those, right?) into the toilet, for an hour, add salt, and extreme pressure, and you’d know what we were thinking when it came out on deck.

Now for the insanely good luck. Triage in main science begins with getting the modem housing open. Since seawater rushed into the housing at potentially 200 meters, you can’t just open it because the remaining air inside is still under pressure. “But won’t the water just get out the same way it got in?” you ask. No, because holding in water is not the same as keeping it out. Think about how your car door only opens outward. Anyway, the flooded housing was opened as slowly as possible but it still had enough pop to explode in my hands. Breaking some screws and scaring the pants off Greg. If we had gone to 1.5 kilometers the housing would have blown my hand off, a hole in the sink and still had enough oomph to go through the hull.

Once we got the electronics out we followed standard, “electronics rescue procedures at sea”. Boards are scrubbed with a brush in alcohol and deionized water, then hot air dried as you examine them for any corrosion. Let me cut to the chase. The boards still worked! A miracle! Only, it wasn’t…

And now, bad luck. As we continued to run and test the boards, I resealed the housings with fresh o-rings and grease. In doing so I found the flaw that led to our housing failure; The origin of the problem was that when the housing is screwed shut, the boards could catch on a surface and release pressure on an o-ring while the system was at atmospheric pressure. If this particular o-ring releases from its groove then the high-pressure salt water will push it right through into the can. So we did a pressure test of the now re-sealed empty housings down to 500 meters and they held as they were intended to do. It seemed like we were a go. But, and here’s the thing about salt water corrosion, it continues even once you’re dry. By the time we were ready to deploy again, the boards ceased functioning.

Finally, the fighting chance. WHOI electronics engineer, Al Duester, has a kit (and a mind for electronics) like no other. Back-ups of back-ups of back-ups of things he might need, ad infinitum. From resistors to oscilloscopes he’s like a turtle – he carries it all on his back. I wouldn’t say it to his face but when it hits the fan, “Let the Dues loose!” So Al gave us a back-up computer of a type similar to the one we lost. The beach team has written new code for it since it required different library files and Greg is busy as I’ve ever seen him soldering new connections and overcoming wiring issues.

The weather report for our last full day at the ranch indicated afternoon showers, but clear in the morning until about noon. We decided to get one last 2 hr low band measurement taken in the morning. On our way back the previous day, we noticed a spot 15 miles south of the ranch that looked favorable.

As we loaded the car, the tire pressure indicator warned us that we were low 5 psi in one tire. We exited the car, had a look, and discovered it to be worse than just 5 psi. The tire was half flat.

Luckily, John and the ranch hands had not gone into the field yet and were still working in the area. So we asked them if they could help us with our tire. They pumped it up with air and then we easily heard where the leak was – on the bottom of the tire right in the middle and was caused from hitting one too many sharp rocks. The tire couldn’t be patched, it was a dead tire.

John knew of a tire repair place in Austin, Nv, just 50 miles away. The man had a tire our size, and agreed to come up the road from Austin to deliver and install the new tire (actually a used tire). The deal was on.

Raul and I drove to our observation site using the spare tire (not a full sized spare) and began setting up the morning’s observation. 10 minutes later, the repair man pulled up with his truck and proceeded to take care of our tires. Amazingly the whole ordeal only set us back about one hour. We thanked him profusely and paid him profusely, but it was worth it. He said, “this is my job, I fix tires.” And he was a very busy man indeed. He was one of the tire shops selected to patch the huge tires for one of the mining companies. He told us that those tires were very lucrative to repair.

The sky was clear when we started but we knew it was going to be a race against time. Hour one: completed. Skies looking a little more ominous. Hour two of measurement began: how long would the sky hold off? We waited a bit too long and the high winds came. We furiously tried to shut down the computer cleanly, but the wind and now rain droplets were coming down too fast. Our shade structure twisted into a pile of rubble. We did manage to get the computer and instruments back into the car with no damage to them or us.

We unpacked the car at the ranch, as it had not started to rain there yet, and repacked it properly. That hour of delay from the flat tire did cost us as we really needed that extra hour.

As we were recovering from the earlier mayhem, the AC suddenly shut off and all was quiet – the power went out. OK, what next?! Fortunately, dinner was being cooked on the gas grill and we would not be denied our dinner. In the meantime, I went down to the hot spring hoping to cool off. The end of the pond away from the spring was indeed cool and it felt very nice to wash the dust off and cool off in the hot spring (luckily we are from Phoenix and have an altered sense of hot and cold). Showers at the cabin were out of the question as the cold water was too hot to stand under.

We had a very nice dinner with the ranch manager John, with his wife, two daughters, the daughter’s 3 little boys (ages 3, 5, and 7), the daughter’s boyfriend (also the head ranch hand), and one college intern. We had great discussions about cattle, the history of the ranch and surrounding area, and of course, John wanted to know more about the topic we were studying.

And to cap off dinner, the power came back on after being out for nearly 6 hrs. The day had a rough beginning, but a pleasant ending.

We are now headed back to Arizona and are examining the data we collected.

We processed our data from the previous day and noticed that the high band antenna had considerable radio frequency interference (RFI), but that the low band was much quieter. To view the antenna response, we plot the antenna temperature (basically power) vs frequency. An ideal plot would be a smooth curve, but when RFI is present, there will be occasional narrow RFI spikes at various frequencies.

The frequency of FM radio is in the range of 88 to 108 MHz. Despite the lack of FM reception on our car’s radio, the low and high band antennas picked up a forest of spikes in the Radio Band. It appears one can not escape FM radio.

Other than FM radio, the low band interference was not that bad. We decided to use day 4 to search the area for other locations which were good in the low band, by using our small biconical dipole antenna and measure for 10 minutes for a NS orientation and 10 minutes for an EW orientation.

We traveled a 180 mile loop around the area, stopping in various (4) places. The loop took us 9 miles north of the ranch on Nevada Hwy 21 (Grass Valley Rd) and then 21 miles westbound on another road (name unknown) to Hwy 278. Going south on 278 for 41 miles brings you to Eureka, the first decent sized town in the area. The next part of the loop is 69 miles of Hwy 50 (westbound), which meets up with Hwy 21. 40 miles of the gravel road Hwy 21 brings us back to Gund Ranch.

We tried 4 locations. The first location was on the road whose name we are uncertain of. We were able to get in a full measurement. The second location was a few miles south on Hwy 278 near the Alpha ranch. Our measurement there was cut short by about 5 minutes due to a rain cloud that popped up suddenly. Our third measurement was 30 miles into Hwy 50. That measurement was called off due to rain before we could even set up. The fourth measurement was also off of Hwy 50, but about 5 miles north of there on a side road.

We did get in some measurements on day 4 despite the rain. However, lightening did add spurious RFI to our data, and the data might not appear as clean as it should actually be.

At the end of the day, the Ranch Manager, John, paid us a visit and confirmed an earlier invitation to us to have dinner with him and his wife at his house the next day (steak from his cattle), but there would be additional guests because his wife had reminded him that it was his birthday tomorrow!

The EDGES program under Professor Judd Bowman is searching for a site which would be nearly as remote and quiet (in the radio frequency ranges of 50-200 MHz) as the current site in Western Australia, but slightly more convenient to get to for testing and development. The Global Epoch of Reionization (EOR) signal is very faint and must be carefully extracted from a bright sky almost 100,000 times greater in magnitude, so the fewer stray signals we pick up, the better our chances of successfully extracting the signal.

It was for this reason that Raul Monsalve (post-doc) and I (PhD candidate) packed a nice new SUV rental with our antenna gear last Monday and headed off to the middle of Nevada. It’s a long trip, so we were forced to spend the first night in Las Vegas. And on the second day, via the extraterrestrial highway (318), we arrived at the Gund Research Ranch operated by the University of Nevada Reno. (http://www.ag.unr.edu/about/facilities/gund_ranch.aspx). During the drive on the second day, we were encouraged by the weakness (and most of the time the lack of reception) of FM radio stations.

The ranch manager had a nice empty cabin available and was very hospitable. He showed us the boundaries of the ranch (100,000 acres when considering public and private lands) and told us of the hot springs in the area. One undesirable by-product of the hot springs is that the longer you let the cold water run, the hotter it gets, to the point of scalding. The ranch research focuses mainly on cattle, but people come to the ranch to conduct research on a variety of topics. He also pointed out several spots in the field that might interest us which didn’t have cattle roaming around that we might want to visit the next day.

On the third day, we took the packed SUV out onto a field on the ranch property. The rancher warned us to get out of there asap if it started to rain, because the road would get slick as butter and we’d have no chance of exiting. The road consisted of two tire tracks without vegetation amid a field that was a forest of thriving desert scrub brush plants. After going into the field for about a mile, and fearing we might not come back out if we drove much further, we found a place to set up our antenna and take measurements.

We brought 3 antennas with us and took measurements with all of them at this site:
1) A low band antenna sensitive in the range of 50 to 125 MHz
2) A high band antenna sensitive in the range of 80 to 200 MHz.
3) A small biconical dipole antenna sensitive in the range of 50 MHz and above.

After 2 hrs, we set up the low band antenna and took 2 hrs of measurements. We then switched antennas and took 2 hrs of measurements with the high band antenna. Because at 2 pm a few drops began to fall during the high band measurements, we decided to make the bi-conical dipole measurements in parallel to hasten our departure (we could do this because the dipole used a different piece of equipment than the low and high band antennas). If it really started to rain, there was no way we could shut down and get out of there in under 40 minutes, so we foolishly took our chances and completed all of our measurements. Luckily the few drops of rain stopped and we made an uneventful return to the ranch.

We are now looking at the data we recorded and will update you on the results in the next blog entry.

The theme of this cruise, the common thread that binds all the research going on, is future instrumentation and sensor development. Researchers from Woods Hole Oceanographic Institution, Lamont–Doherty Earth Observatory, University of Idaho, University of Minnesota, Institute GNS Science (New Zealand), and of course, Arizona State University’s School of Earth and Space Exploration have come together on this cruise to push the boundaries of measurement in the most extreme place on earth, the hydrothermal vents at the bottom of the ocean.

The world of the deep ocean is way beyond intuitive experience. The first difference between surface water and deep water is the total lack of light. The last of the sun’s photons having been absorbed nearly 1.3 kilometers above you in the first 200 meters of ocean called the photic zone. It is absolutely pitch dark at the bottom, the only light we see is what we bring and what is produced by occasional marine animals. There are no plants here, only animals. The second difference is the pressure. Seawater is about three times as dense as a skyscraper – no steel beams or concrete but much less empty space. The Empire State Building has a density of about 342 kilograms per cubic meter and seawater has a density of about 1027 kilograms per cubic meter. That means 1.5 kilometers ocean depth is equivalent to having a 4.5 kilometer tall building on your head! Ironically, the only thing that saves you is that it also presses in on you in all directions. Alvin’s small titanium sphere (that three of us squeeze into), “the ball”, is spherical precisely because we exchange structural strength for material strength through the use of the sphere’s basic shape. The third difference is the water itself. In contrast to the approximately 2 to 4 °C ambient water temperature at these depths, water escapes from the vents at temperatures ranging from 60 to 460 °C. Around Axial these days we are hard pressed to find anything much above 350 °C. Due to high hydrostatic pressure, deep heated water can exist in both liquid form and as a supercritical fluid, possessing physical properties between those of a gas and those of a liquid. Realize that it’s not boiling even when it’s 460 °C! Besides being superheated, the water is also extremely acidic, often having a pH value as low as 2.8 – approximately that of vinegar.

Now let me explain in detail what we are placing on the seafloor and why anyone would want to do that:

Our project involves two different components. The first component relates to a novel, high-temperature glass material which is being developed for future use as a subsurface fluid flow tracer. The second component further develops a new approach to high-speed underwater sensing and wireless communications networks. Both project components are ambitious experiments that progress the mission of the National Science Foundation by providing foundational engineering research with the long-term potential to transform our approach to ocean science, education and policy.

The goal of the first component is to test the stability of a new type of non-toxic, chemically-inert fluorescent glass in hydrothermal vent fluid. If the material can withstand the complex chemical environment of high-temperature vent fluid for an extended duration, it could potentially be used as a tracer for mapping subsurface fluid flow in the future. Such tracer studies will help to address some of the most difficult but fundamental questions we have about the Earth, including: How deep within the Earth does life live? What limits the growth of life in these extreme environments? How large is the subseafloor biosphere, and what role does it play in the carbon cycle? We will test this inert non-toxic material by attaching it to temperature probes and placing the probes in direct contact with high-temperature hydrothermal fluid for 2-3 weeks. Probes will be placed into hydrothermal vents using the Alvin Submersible. We will examine the material before and after vent fluid exposure using fluorescence microscopy, and evaluate any changes in its physical and optical properties.

The goal of the second component is to characterize the range and stability of an optical multi-hop sensor network. Sensor networks employ a spatially distributed array of communicating nodes, in which each node collects and transmits data to its neighbors in a web-like fashion. Sensor networks allow scientists to monitor dynamic phenomena over an extended area simultaneously. Optical multi-hop networks will form an important part of the communication backbone for distributed, underwater sensor data collection to help monitor ocean phenomena over wide areas and volumes. Such networks can be joined by passing Remotely Operated Vehicles ROVs, Autonomous Underwater Vehicles AUVs, or other sensors (like those used to monitor the tracers described above) to relay data to each other or onto a cabled observatory or surface buoy for real-time reporting. On this cruise, we will test two optical modem modules deployed multiple times at varying distances apart along a cable. The data will be statistically combined in order to model and plan for future sensor network missions.

This was a long one, not really suited for a blog perhaps. I hope you made it through and maybe learned a little too.